import React, { Component } from 'react';
import DemoChild3 from './Child3';
class DemoChild2 extends Component {
  render() { 
    return ( <>
      <div>
        用户名2：{this.props.username}
        <DemoChild3 username={this.props.username}/>
      </div>
    </> );
  }
}
 
export default DemoChild2;